JPH08231165A - Guide shoe - Google Patents

Abstract

PURPOSE: To promote an improvement in quality and a reduction in cost by making up a lubricative rubber composition forming a slider from such made up of mixing those of fluororubber, thermoplastic fluororesin and low molecular weight content fluoropolymer at a specified rate, in this guide shoe which guides the opening or closing movement of an elevator door or the like. CONSTITUTION: An elevator door is slidingly guided of its lower part into a sill groove via a guide shoe which is composed of attaching a rubber elastic body to a mounting bracket 1 and also a slider 2 to this rubber elastic body, and it is formed into almost rectangular form as a whole. In this case, it is made up of a lubricative rubber composition being composed of containing this slider 2, fluororubber, thermoplastic fluororesin, and a low molecular weight content fluoropolymer of no more than the number-average molecular weight 5×10<4> , and whose compounding weight percentage of fluororubber and thermoplastic fluororesin is the range of 50:50 to 95:5, and a compounding quantity of the low molecular weight content fluoropolymer to the total 100 pt.wt. of the fluororubber and the thermoplastic fluororesin in the 5 to 50 parts by weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide shoe for smoothly guiding opening / closing movement of a moving body such as an elevator door.

[0002]

2. Description of the Related Art Generally, there are elevator doors for car entrances and entrances and entrances for entrances and exits. Both of them are suspended and supported by a hanger rail slidably through a door hanger.
The structure is such that the lower part is slidably guided through the guide shoe into the threshold groove of the entrance.

As shown in FIG. 2, a guide shoe which has been conventionally used is a mounting member 11 connected to a lower portion of an elevator door by a bolt or the like, a rubber elastic body 12 integrally mounted to the mounting member 11, The sliding body 13 is integrally mounted on the rubber elastic body 12, and has a generally oblong rectangular parallelepiped shape as a whole.

The sliding body 13 has a shape that surrounds the outer circumference of the rubber elastic body 12, has a thickness (usually 1 mm or less) that does not impair the elastic force of the rubber elastic body 12, and is made of nylon or fluororesin. Made of friction material. Then, the front and rear sliding surfaces are brought into sliding contact with the wall surface of the threshold groove to smoothly guide the opening / closing movement of the door.

In the above guide shoe, usually, the mounting member 11 and the sliding body 13 made of nylon or the like are integrally formed by injection molding (insert molding), and then the mounting member 1
It was formed by integrally vulcanizing (insert molding) the rubber elastic body 12 integrally with 1 and the sliding body 13.

Alternatively, a sheet material such as a fluororesin which can be adhered is stretched on the outer periphery of the rubber elastic body, and in this state, the mounting metal fitting, the sliding body and the rubber elastic body are heated and integrally vulcanized. (See Japanese Patent Laid-Open No. 281821/1990).

[0007]

A guide shoe in a moving body such as an elevator door is engaged with a groove such as a threshold groove,
Since it has a function of smoothly sliding and guiding the moving body, it is required to simultaneously have good sliding characteristics with respect to the groove and good cushioning characteristics capable of absorbing lateral shake load when the moving body is opened and closed. The reason why the conventional product adopts the integral structure composed of the sliding body made of a low friction material and the rubber elastic body is none other than satisfying this requirement.

However, in the conventional structure in which the mounting member and the sliding body are integrally injection-molded, and then the rubber elastic body and the vulcanization mold are integrally molded, insert molding is performed twice by the injection mold and the vulcanization mold. The positional deviation between the mounting bracket and the molded body was likely to occur, and the probability of failure was high.

Further, in the conventional structure in which the mounting member, the sliding body and the rubber elastic body are vulcanized and bonded, the sheet material such as the fluororesin, which becomes the sliding body, needs to be treated so that it can be adhered, so that the manufacturing process is complicated. there were.

An object of the present invention is to eliminate the need for double insert molding in the conventional guide shoe and the process for adhering the sliding body, thereby improving the quality of the guide shoe, reducing the cost, and simplifying the manufacturing process. The aim is to stabilize the function for a long period of time.

[0011]

According to the present invention, a sliding body of a guide shoe of a moving body such as an elevator door is provided with a fluororubber which is a first essential component, a thermoplastic fluororesin which is a second essential component, and 3 essential component number average molecular weight 5 × 10
A low molecular weight fluoropolymer having a molecular weight of ⁴ or less, the first
The compounding weight ratio of the fluororubber which is an essential component and the thermoplastic fluororesin which is the second essential component is in the range of 50:50 to 95: 5, and the fluororubber which is the first essential component and the second essential component. It was formed from a lubricating rubber composition in which the content of the low molecular weight fluoropolymer as the third essential component was 5 to 50 parts by weight based on 100 parts by weight of a certain thermoplastic fluororesin.

The fluororubber, which is the first essential component, is a polymer or copolymer of unit monomers containing one or more fluorine atoms on average and has a glass transition point of room temperature or lower. There is no particular limitation as long as it has rubber-like elasticity at room temperature, and a wide range can be adopted.

The fluororubber as the first essential component is a vinylidene fluoride-fluoropropylene copolymer, a tetrafluoroethylene-propylene copolymer, a vinylidene fluoride-hexafluoropropylene copolymer, or a vinylidene fluoride-hexafluoropolymer. One or more fluororubbers selected from the group consisting of propylene-tetrafluoroethylene copolymer, fluorosilicone fluororubber, phosphansen fluororubber and perfluoro fluororubber can be employed.

As the polymerization method of the above-mentioned fluororubber, there can be adopted various polymerization methods such as bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, catalyst polymerization, ionizing radiation polymerization and redox polymerization. . Further, the number average molecular weight (Mn) of the above-mentioned fluororubber is usually preferably 5 × 10 ⁴ or more, more preferably 7 × 10 4 since a high molecular weight one can obtain a good effect. ^Four
Above all, particularly preferably about 10 × 10 ^{4 to} 25 × 10 ⁴ .

Commercially available fluororubbers satisfying the above conditions include vinylidene fluoride-fluoropropylene copolymer "Technoflon" manufactured by Audimond Co., and tetrafluoroethylene-propylene copolymer manufactured by Asahi Glass Co., Ltd. "Afras" and other vinylidene fluoride-hexafluoropropylene copolymer manufactured by DuPont Showa Denko "Viton", etc., vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer manufactured by Montefluos "Technoflon" , Etc., such as "Silastic LS" made by Dow Corning, which is a fluorosilicone fluororubber, "PNF" made by Firestone Co., which is a phosphansen fluororubber, and "Perkin fluororubber made by Daikin Industries". You can exemplify That.

The thermoplastic fluororesin which is the second essential component is a tetrafluoroethylene-ethylene copolymer, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer. One or more polymers selected from the group consisting of can be employed.

As the polymerization method of the above-mentioned thermoplastic fluororesin, each polymerization method such as catalyst emulsion polymerization, suspension polymerization, catalyst solution polymerization, gas phase polymerization, and ionizing radiation irradiation polymerization can be adopted. . The Mn of such a thermoplastic fluororesin is usually preferably 5 × 10 ⁴ or less, and more preferably more than 5 × 10 ³ and almost 2 × 10 ⁴ or less.

Commercially available thermoplastic fluororesins satisfying the above conditions include PFA “MP10” manufactured by Mitsui DuPont Fluorochemicals, and FEP “Teflon FEP100” manufactured by Mitsui DuPont Fluorochemicals.
Etc. "Aflon COP" manufactured by Asahi Glass Co., Ltd., which is ETFE, and the like can be exemplified.

Other usable thermoplastic fluororesins include tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE) and trifluorochloroethylene polymer (CT).
FE), trifluorochloroethylene-ethylene copolymer (ECTFE), polyvinyl fluoride (PV
F), polyvinylidene fluoride (PVDF) and the like.

The low molecular weight fluoropolymer, which is the third essential component, is a tetrafluoroethylene polymer (TF
It is possible to employ one or more polymers selected from the group consisting of E), fluoropolyethers and polyfluoroalkyl group-containing compounds.

The composition obtained by mixing the fluororubber as the first essential component and the thermoplastic fluororesin as the second essential component as described above has properties as an elastic body, but has a low molecular weight as the third essential component. The fluoropolymer is added to the composition having such properties as an elastic body in order to impart excellent sliding properties.

Here, the low molecular weight fluoropolymer is
Tetrafluoroethylene (TFE), main structural unit-C
A fluoropolyether having _n F _2n —O— (n is an integer of 1 to 4), a polyfluoroalkyl group-containing compound (having 2 to 2 carbon atoms) having a main structural unit represented by the following chemical formula 1.
20) refers to those having a molecular weight (Mn) of 5 × 10 ⁴ or less, but in order to impart more excellent sliding characteristics, Mn 5 × 1
Those of 0 ³ or less are particularly desirable.

[0023]

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Of these, a TFE low-order polymer having an average particle size of 5 μm or less is most desirable, and as a commercial product,
Examples include “Vydax AR” manufactured by DuPont, “Fluon Lubricant L169” manufactured by Asahi Glass Co., Ltd., and the like.

The above-mentioned fluoropolyether having an average molecular weight of 5 × 10 ⁴ or less and having a main structure of —C _n F _2n —O— (n is an integer of 1 to 4) is represented by the following chemical formula 2. Can be illustrated.

[0026]

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In order to improve the affinity (adhesion) to other compounding materials and additives, such polymers are those having a structural unit containing a functional group such as an isocyanate group, a hydroxyl group, a carboxyl group and an ester group. desirable.

Specific examples of such a fluoropolyether include those represented by the following chemical formula 3,
These may be used alone or in combination with those having no functional group.

[0029]

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Further, a fluoropolyether having a functional group containing activated hydrogen and an isocyanate compound having no polyfluoropolyether group may be used in combination,
Further, a fluoropolyether having an isocyanate group may be used in combination with diamines or triamines containing no various fluoropolyether groups or diols or triols containing no various fluoropolyether groups.

In particular, it is preferable to use a combination of fluoropolyethers in which the functional groups react with each other to increase the molecular weight. Examples of such fluoropolyethers include those having a unit containing an isocyanate group and hydroxyl groups. Combining with those containing units is likewise preferred.

As the above-mentioned polyfluoroalkyl group-containing compound, for example, there is a compound having a polyfluoroalkyl group represented by the following chemical formula 4, which has 2 carbon atoms.
Specific examples of the compound having an average molecular weight of 5 × 10 ⁴ or less and a compound having a reactive group and a polyfluoroalkyl group and a group that reacts with the reactive group are shown as specific examples. A polymer of a reaction product with an ethylenically unsaturated compound (for example, a fluoroalkyl acrylate), a compound having the above-mentioned reactive group and a polyfluoroalkyl group, and various polymers having a group reactive with the reactive group Reactants, or polycondensates of the above compounds}.

[0033]

[Chemical 4]

[0034]

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Like the above-mentioned fluoropolyether, such a polyfluoroalkyl group-containing compound is a functional group having a high affinity for improving the affinity (adhesion) of other compounding materials and additives. For example isocyanate groups,
Hydroxyl group, mercapto group, carboxyl group, epoxy group,
A compound having a unit containing an amino group, a sulfone group or the like is preferable.

The polyfluoroalkyl group-containing compound may be used alone or in combination of two or more kinds. Also, a polyfluoroalkyl group-containing compound having a reactive group having activated hydrogen and an isocyanate compound having no polyfluoroalkyl group may be used in combination. Also,
A polyfluoroalkyl group-containing compound having an isocyanate group may be used in combination with various polyfluoroalkyl group-free diamines, triamines or various polyfluoroalkyl group-free diols and triols.

The combination of such functional groups is preferable also from the viewpoint of increasing the strength. Specifically, it has a polyfluoroalkyl group having 2 to 20 carbon atoms, and has a hydroxyl group, a mercapto group, a carboxyl group and an amino acid. In combination with a fluoropolymer containing at least one selected from the group consisting of, or having a polyfluoroalkyl group having 2 to 20 carbon atoms, and having a unit containing an isocyanate group, and a C 2 to 20 Examples thereof include a combination with a fluoropolymer having a unit having a polyfluoroalkyl group and further having a reactive group having activated hydrogen.

In particular, when a fluoroolefin polymer or fluoropolyether is used among these low molecular weight fluoropolymers, an excellent effect on lubricity is obtained, and particularly, tetrafluoroethylene polymer having an average particle diameter of 5 μm or less is obtained. It has been found that the use of coalescence produces the most desirable effect.

The compounding ratio of the above-mentioned first essential component fluororubber, the second essential component thermoplastic fluororesin and the third essential component low molecular weight fluoropolymer is as follows:
The weight ratio of fluororubber to thermoplastic fluororesin is 50:
A range of 50 to 95: 5 is desirable. This is because if the blending weight ratio of the thermoplastic fluororesin exceeds 50/100, sufficient elasticity cannot be obtained for the target composition, and if it is less than 5/100, sufficient abrasion resistance cannot be obtained.

Further, the low molecular weight fluoropolymer 5 is added to 100 parts by weight of the fluororubber and the thermoplastic fluororesin in total.
˜50 parts by weight is preferred. If the compounding ratio of the low molecular weight fluoropolymer is less than 5 parts by weight, sufficient sliding properties cannot be obtained, and 5
This is because if the amount exceeds 0 parts by weight, the rubber-like elastic properties are impaired.

Further, with respect to the above-mentioned lubricating rubber composition, 3
Abrasion resistance can be improved by adding a thermosetting resin powder which is not melted at 00 ° C or a heat resistant resin powder having a glass transition point of 300 ° C or higher.

The thermosetting resin powder is a fine powder after thermosetting such as a phenol resin or an epoxy resin, and the heat-resistant resin having a glass transition point of 300 ° C. or higher is a polyimide resin, an aromatic polyamide resin or the like. The fine powder of. Among commercially available resin powders, "Bellpearl H300" manufactured by Kanebo Co., Ltd. is used as a hardened and ground product of phenol resin, and "PWA2" manufactured by Mikasa Sangyo Co., Ltd. is a hardened and ground product of polyimide resin.
0 ", as a crushed product of aromatic polyamide resin" MP-P "manufactured by Asahi Kasei, and as a thermosetting resin powder having a glass transition point (Tg) of 300 ° C or higher," UPILEX S "(Tg manufactured by Ube Industries) > 500 ° C).

The particle size of such thermosetting resin powder is 1
Those having a particle size of up to 15 μm are preferable from the viewpoint of maintaining rubber-like elasticity and facilitating the kneading process. The thermosetting resin powder may be added in an amount of 5 to 20% by weight with respect to the above-mentioned essential components, and if it is less than 5% by weight, the effect of improving abrasion resistance is not obtained, and if it exceeds 20% by weight, rubber elastic properties are impaired. It is not preferable.

Various additives may be added to the above components as long as the object of the present invention is not impaired. For example, as a vulcanizing agent for fluororubber, isocyanurate, organic peroxide, etc., antioxidant or acid acceptor such as sodium stearate, magnesium oxide, calcium hydroxide, antistatic agent such as carbon, silica, alumina, etc. filler,
Other metal oxides, colorants, flame retardants, etc. may be added as appropriate.

The method for mixing the various raw materials described above is not particularly limited, and is a widely used method, for example, an elastomer as a main raw material and other raw materials are individually and sequentially or simultaneously mixed with a roll mixer or the like. It can be mixed by a machine. In addition, it is desirable to provide a temperature controller for the purpose of preventing heat generation due to friction at this time. Further, when using a roll mixer, it is more preferable to tighten the roll interval to about 3 mm or less and perform thin threading for finishing mixing.

The guide shoe of the present invention does not require a particularly limited means in the molding process, and the primary vulcanization (at 140 to 170 ° C. 1
After performing a pressure of 5 to 10 kgf / cm ^{2 for} 0 to 30 minutes, secondary vulcanization (2 to 20 hours at 200 to 300 ° C., no pressure) may be performed.

The slide body of the guide shoe in the present invention is made of acrylonitrile butadiene rubber as a base material, and tetrafluoroethylene resin powder and thermosetting resin cured powder or glass transition temperature of 300 ° C. or higher. It can also be formed from a lubricating rubber composition containing a plastic resin powder.

The acrylonitrile butadiene rubber (NBR) used in the present invention is not particularly limited as long as it is synthesized by various synthetic methods and has rubber-like elasticity at room temperature, and a wide range can be adopted. it can.

NBR is a copolymer of butadiene and acrylonitrile, and its physical properties can be changed by including the amount of acrylonitrile in about 15 to 50%. The amount of nitrile is, for example, low nitrile less than 24%, medium nitrile 2
4-30%, medium high nitrile 30-36%, high nitrile 3
It can be classified as 6 to 42% and exceeding 42% of extremely high nitrile. In order to increase wear resistance, aging resistance and tensile strength, it is better to use a large amount of nitrile,
The amount of nitrile is preferably in the range of about 24% to 42%, or more than about 24% and less than 42% in order to prevent the rubber elasticity, cold resistance and low temperature properties from being impaired. The above compounding ratio may be either wt% or mol%, but it is desirable to use wt%. Examples of NBR include those having a structure represented by the following chemical formula 6 as a main structural unit. The molecular weight of NBR is usually preferably 50,000 or more, more preferably 7
10,000 or more, and particularly preferably about 100,000 to 500,000 is used.

[0050]

[Chemical 6]

Commercially available NBRs satisfying the above conditions are "JSR-N" manufactured by Japan Synthetic Rubber Co., Ltd., "NIPOL" manufactured by Nippon Zeon Co., Ltd., and "CHEMIGU manufactured by Goodyear Co., Ltd."
M ”and the like can be exemplified.

The powder of the tetrafluoroethylene resin used in the present invention may be, for example, polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (P
FA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-
Powders of resins such as ethylene copolymer (ETFE) and tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE) can be mentioned. Among them, PTFE, PFA, FEP, ET
FE is desirable, especially around the carbon of the skeleton,
Alternatively, a perfluoro-based tetrafluoroethylene resin (PTFE, PFA, FEP) having a structure surrounded by fluorine with a small amount of oxygen or the like interposed is desirable. PTF
Typical physical properties of E, FEP, PFA and ETFE are shown below.

PTFE elongation (%): 200 to 400 Compressive strength (kgf / mm ² ): 120 Flexural modulus (10 ³ × kgf / mm ² ): 5.6 Shore hardness: D 50 to 65 Maximum operating temperature (°) C): 260 FEP Elongation (%): 250 to 330 Compressive strength (kgf / mm ² ): 155 Flexural modulus (10 ³ × kgf / mm ² ): 6.6 Shore hardness: D 55 to 65 Maximum operating temperature ( ° C): 200 PFA Elongation (%): 280-300 Compressive strength (kgf / mm ² ): 170 Flexural modulus (10 ³ × kgf / mm ² ): 6.6-8.4 Shore hardness: D60- 64 Maximum operating temperature (° C): 260 ETFE Elongation (%): 100 to 470 Compressive strength (kgf / mm ² ): 500 Bending elastic modulus (10 ³ × kgf / mm ² ): 9 to 14 Shore hardness: D75 Maximum operating temperature (° C): 150 to 180 If the resin composition is in the above range of elongation, compressive strength, flexural modulus, hardness, temperature characteristics, etc., moderate elasticity and hardness required for guide shoes in general. It is considered that it can be applied to static friction characteristics, etc., and can improve wear resistance and sliding characteristics.

Two or more kinds of the above tetrafluoroethylene resin powder may be appropriately mixed in order to further improve lubricity, heat resistance and the like. In order to increase the strength and the like, glass fibers, carbon fibers, inorganic fibers such as potassium titanate and the like, organic fibers such as aramid fibers and polyester fibers, talc, mica, graphite, glass flakes, carbon, calcium carbonate and An inorganic filler material such as molybdenum sulfide may be filled. Further, in order to further improve abrasion resistance and the like, thermosetting resin such as epoxy resin, phenol resin, polyimide resin, polyphenylene sulfide resin (PPS), polyether ether ketone resin (PEEK) and other ketone resins. Resin, aromatic polyester resin, thermoplastic polyimide resin (P
You may mix | blend thermoplastic resins, such as I), a polyamide imide type resin (PAI), and a polyether imide type resin (PEI). The filler and resin as described above are, for example, about 5 to 5.
About 50 parts by weight, preferably about 5 to 25 parts by weight, and two or more kinds may be appropriately blended within a range of about 5 to 15 parts by weight. In addition, when mixing two or more kinds, the mixing ratio may be determined according to the mixing ratio exemplified here.

The tetrafluoroethylene-based resin powder may be either a molding powder produced by a suspension polymerization method or a fine powder produced by an emulsion polymerization method. After crushing or crushing, γ-ray irradiation treatment or electron beam irradiation treatment after crushing, or γ-ray irradiation treatment or electron beam irradiation treatment after polymerization and having an average particle size of 20 μm or less can be used.

Commercially available products of the tetrafluoroethylene resin satisfying the above conditions are "Lubron L10" manufactured by Daikin Industries, "Fluon G163""FluonCD1""LubricantL169" and "Lubricant L182J" manufactured by Asahi Glass Co., Ltd. "Teflon 7J" manufactured by Mitsui DuPont Fluorochemical Co., Ltd. can be exemplified.

Furthermore, as shown in FIG. 3 in an enlarged form, the tetrafluoroethylene-based resin powder has a carbon material 21 made of graphite or the like projected on the surface of the tetrafluoroethylene-based resin powder 20, so-called stabbed. Those in the state are more preferable. The tetrafluoroethylene-based resin powder in such a form can be obtained, for example, by coprecipitating with a carbon material, coagulating, washing, and drying at the end of emulsion polymerization in the production of fine powder. Alternatively, it can also be obtained by dry-mixing a carbon material with a resin powder and making it stick into the surface. The carbon material here may be powdered products in various crystal states from general carbon powder to graphite, but graphite is particularly preferable because the crystal structure due to graphitization is expected to have lubricity. Further, it may be HAF, SAF, FEF, MT or the like of carbon black having a large structure which is generally used as a rubber material.

In the tetrafluoroethylene-based resin powder having the above-mentioned configuration, as shown in FIG. 3, since the carbon material 21 made of graphite or the like is projected in all directions (radiation direction), the rubber base material 22 is formed. Since it has a physical pile effect inside and the affinity between the rubber base material 22 and the carbon material 21 is good, a material having a higher strength than that obtained by kneading the rubber material and normal tetrafluoroethylene resin powder is obtained. To be

The average particle size of the tetrafluoroethylene resin powder is not particularly limited, but is preferably within 20 μm from the viewpoint of rubber elasticity and surface hardness of the molded product,
About 20 μm is more preferable. This is because if the average particle diameter exceeds 20 μm, the rubber hardness becomes high and the rubber elasticity may be lost, and if it is less than 5 μm, sufficient abrasion resistance cannot be obtained.

In the present invention, the blending weight ratio of NBR to tetrafluoroethylene-based resin powder is 10 to 10 parts by weight of NBR.
It is preferably 100 parts by weight. If the amount of the tetrafluoroethylene-based resin powder is less than 10 parts by weight, the NBR cannot have a sufficiently low frictional property, and if it is blended in a large amount in excess of 100 parts by weight, the rubber hardness becomes high and the elastic properties are impaired. This is because the mechanical strength is extremely reduced and it cannot be put to practical use.

As the cured powder of the thermosetting resin or the thermoplastic resin powder having a glass transition point of 300 ° C. or higher in the present invention, various ones exemplified above can be used. The blending weight ratio of the cured powder of the thermosetting resin or the thermoplastic resin powder is 5 to 80 parts by weight with respect to 100 parts by weight of NBR. If less than 5 parts by weight, NB
If R is not sufficiently wear-resistant and a large amount is blended in excess of 80 parts by weight, rubber hardness becomes high and elastic properties are impaired, or mechanical strength is extremely reduced, and it cannot be put to practical use. Because. From such a tendency, the more preferable blending weight ratio of the cured powder of the thermosetting resin or the thermoplastic resin powder having a glass transition point of 300 ° C. or higher is NBR.
It is 5 to 30 parts by weight with respect to 100 parts by weight.

Instead of the cured powder of the thermosetting resin or the thermoplastic resin powder having a glass transition point of 300 ° C. or higher,
Spherical graphite can also be used. As spherical graphite,
Examples thereof include spheroidal graphite produced as a by-product in the step of spinning from pitch, or a sphere-shaped graphite obtained by reacting a phenol resin with paraformaldehyde under a catalyst to polymerize it into spheres, and then calcinated and pulverized. The spherical graphite used in the present invention preferably has a primary particle size of 1 to 200 μm, preferably 1 to 40 μm, and more preferably 5 to 40 μm. If the particle size is less than 1 μm or 5 μm, when it is dispersed and mixed in NBR and exposed on the sliding surface, it will be buried due to elastic deformation due to the pressure of NBR, and the load will be supported in contact with the sliding mating material. This is because, when the diameter is larger than 200 μm, the smoothness of the sliding surface is deteriorated, which is not preferable. Further, the outer shape of such spherical graphite may be not only a spherical surface having a smooth surface but also a surface having some irregularities. The preferable blending weight ratio of the spherical graphite in the present invention is 5 to 8 relative to 100 parts by weight of NBR for the same reason as above.
0 parts by weight.

The method for producing spherical graphite will be described below. In the present invention, the method for producing the spherical graphite is not particularly limited, but so-called liquid phase carbonization method or solid phase carbonization method is suitable for obtaining predetermined primary particles. Manufacturing examples include the following (1) to (3).

(1) Phenolic resin, naphthalene resin,
Furan resin, xylene resin, divinylbenzene polymer,
Using at least one of styrene-divinylbenzene copolymer as a starting material, spherical particles are prepared from these raw materials by a known emulsion polymerization method, and the spherical particles are further subjected to an inert atmosphere such as nitrogen gas or argon gas or under vacuum. Carbonize (and / or) graphitize by firing below.

(2) A novolac-type or resol-type phenol resin produced by using a formalin-generating compound for phenols, if necessary, may contain a known filler, and as it is or as a cross-linking agent such as hexamethylenetetramine. Is added and heated to obtain a cured product, which is then pulverized to a predetermined particle size.

(3) By heating coal tar or coal tar pitch to 350 to 500 ° C., spherical graphite produced by polymerization reaction of low molecular weight substances is separated and purified.

Commercial products of the above spherical graphite include:
Examples include "Mesocarbon beads" manufactured by Osaka Gas Chemicals, "Bellpearl" manufactured by Kanebo, "Univex" manufactured by Unitika, "Microcarbon beads" manufactured by Nippon Carbon Co., Ltd., and the like.

It is needless to say that a known compounding agent for rubber or a known additive may be compounded in the present invention. (1) Reinforcing agent: carbon black, silica, clay, calcium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum oxide, talc, mica, kaolin, bentonite, shirasu, wollastonite, silicon carbide,
Glass powder, carbon powder, boron fiber, aramid fiber, etc. (2) Vulcanization aid: zinc white, fatty acid, etc. (3) Vulcanization accelerator: guanidines, sulfurs, aldehyde-amines, zinc, etc. (4) Plasticizers: dimethyl phthalate, dioctyl phthalate, etc. (5) Anti-aging agents: amines, phenols, etc. (6) Others: antioxidants, UV absorbers, flame retardants, colorants, etc. Oil, wax, and grease may be added to improve the non-adhesiveness of the surface. The compounding amount is such that the mechanical strength of the rubber molded product is not affected, for example, with respect to 100 parts by weight of NBR,
The amount is preferably 2 to 20 parts by weight, more preferably 5 to 10 parts by weight.

The method of mixing the various materials described above is not particularly limited, and a method that is generally widely used, for example, NBR as the main raw material and other fillers are sequentially mixed or batched individually. Mixing with a roll mixer, propeller mixer, kneader mixer or other mixer. At this time, it is desirable to provide a temperature controller for the purpose of preventing heat generation due to frictional heat. Also, when using a roll mixer, the roll interval is 3 m as finishing mixing.
It is preferable to carry out thin threading as m or less.

In the present invention, an organopolysiloxane containing at least one group selected from a hydroxyl group such as an alcoholic hydroxyl group, an amino group, a carboxyl group, a glycidyl group, and a mercapto group is dispersed in a molding composition. You may keep it. Such an organopolysiloxane may be a homopolymer or a copolymer of two or more kinds of organopolysiloxanes such as dimethylsiloxane, methylphenylsiloxane, and trimethylfluoropropylsiloxane in which a functional group is introduced. Such an organopolysiloxane includes, for example, the following chemical formula 7 in the main structural unit, and specifically includes the following chemical formula 8 in the main structural unit.

[0071]

[Chemical 7]

[0072]

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Further, in the present invention, as described above, a hydroxyl group such as an alcoholic hydroxyl group, an amino group, a carboxyl group, an ester group, an isocyanate group, a sulfone group, an epoxy group and a mercapto group are contained. Such a fluoropolymer may be dispersed and held in the molded body composition. Such fluoropolymers include polyfluoroalkyl group-containing compounds, polyfluoroethers, and the like, and may be those in which at least one of the above functional groups is introduced. Such fluoropolymers include, for example, those containing —C _X1 F _2X1 —O— (wherein X1 represents an integer of 1 to 4) as a main structural unit, and also have a number average molecular weight of about The thing of 1000-5000 etc. are mentioned, Specifically,
“FOM” manufactured by Montecatini Co. represented by the following chemical formula 9
BLIN Z DISOC ”and the like.

[0074]

[Chemical 9]

The number average molecular weight of the above-mentioned organopolysiloxane or fluoropolymer may be about 300 to 10,000, preferably about 1000 to 5,000.

[0076]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

As shown in FIG. 1, the guide shoe of this embodiment includes a mounting member 1 connected to the lower portion of an elevator door (not shown) with bolts or the like, and a lubricating rubber integrally mounted on the mounting member 1. It is composed of a sliding body 2 made of a composition, as shown in FIG.
The conventional rubber elastic body 12 shown in FIG.

In the first embodiment of the present invention, the lubricating rubber composition constituting the sliding body 2 has a fluororubber which is a first essential component, a thermoplastic fluororesin which is a second essential component, and a third Number average molecular weight (Mn) 5 x 1 which is an essential component
A low molecular weight fluoropolymer having a molecular weight of 0 ⁴ or less, and the compounding weight ratio of the fluororubber to the thermoplastic fluororesin is 50:
It is in the range of 50 to 95: 5, and the compounding amount of the low molecular weight fluoropolymer is 5 to 50 parts by weight based on 100 parts by weight of the total of the fluororubber and the thermoplastic fluororesin.

Further, in the second embodiment of the present invention,
The lubricating rubber composition constituting the sliding body 2 is made of acrylonitrile butadiene rubber (NBR) as a base material, tetrafluoroethylene resin powder, thermosetting resin powder or thermoplastic resin having a glass transition point of 300 ° C. or higher. Resin powder is blended, or spherical graphite is blended in place of thermosetting resin powder or thermoplastic resin powder having a glass transition point of 300 ° C. or higher.

[0080]

【Example】

[Examples 1 to 9 and Comparative Examples 1 to 8] Examples 1 to 9 relate to the first embodiment of the present invention. Example 1
9, the materials used in Comparative Examples 1 to 8 are collectively shown below,
Table 1 shows the mixing ratios of the examples, and Table 2 shows the mixing ratios of the comparative examples. The mixing ratio of each component is% by weight. Although not shown in the table, in all of the examples and comparative examples, 5 parts by weight of carbon and 1 part by weight of sodium stearate are used in parts by weight based on the total weight 100 of the raw materials shown in (1) to (12). Parts, 3 parts by weight of magnesium oxide, and 6 parts by weight of calcium hydroxide are added. In addition, (1
Also for the raw materials shown in 3) to 17),
It is shown in parts by weight with respect to 100 as the total weight of the raw materials shown in 2). (1) Elastomer of vinylidene fluoride / fluoropropylene copolymer (fluororubber a: "Technoflon FOR420" manufactured by Ausimont) (2) Elastomer of tetrafluoroethylene / propylene copolymer (fluororubber b: "Aflas" manufactured by Asahi Glass Co., Ltd.) (3) Vinylidene fluoride / hexafluoropropylene copolymer elastomer (fluorine rubber c: manufactured by Daikin Industries, Ltd.)
Daier ") (4) Vinylidene fluoride / hexafluoropropylene /
Tetrafluoroethylene copolymer elastomer (fluorine rubber d: "Technoflon" manufactured by Ausimont) (5) Fluorosilicone elastomer (fluorine rubber e: "Silastic LS" manufactured by Dow Corning) (6) Perfluoroelastomer ( Fluorine rubber f: "Daiel Perflo" manufactured by Daikin Industries, Ltd.) (7) PFA (thermoplastic fluororesin a: Mitsui DuPont Fluorochemicals "MP10") (8) FEP (thermoplastic fluororesin b: Mitsui DuPont) "Teflon FEP100" manufactured by Fluorochemical Co., Ltd. (9) ETFE (thermoplastic fluororesin c: "Aflon COP" manufactured by Asahi Glass Co., Ltd.) (10) TFE (low molecular weight fluoropolymer a: "Fluon Lubricant L169" manufactured by Asahi Glass Co., Ltd.) (11) Fluoropolyether (low molecular weight fluoropolymer b: a Uzimont's "Fomblin Z-DISO
C ") (12) Polyfluoroalkyl group-containing compound (low molecular weight fluoropolymer c:" reagent perfluorononanoic acid "manufactured by Fluorochem) (13) Phenolic resin (PH:" Bellpearl H300 "manufactured by Kanebo Co., Ltd.) ( 14) Carbon (“MT carbon” manufactured by Van der Ville company) (15) Sodium stearate (general industrial material) (16) Magnesium oxide (general industrial material) (17) Calcium hydroxide (general reagent) (18) Nitrile Butadiene rubber (NBR: general industrial material, hardness JIS-A70) (19) Graphite-added polytetrafluoroethylene resin (PTFE: NTN Precision Resins Co., Ltd. "BEAREE FL3"
040 ") (20) Glass fiber-added nylon 66 (PA66: BA)
SF made "A3HG5")

[0081]

[Table 1]

[0082]

[Table 2]

[Examples 1 to 9 and Comparative Examples 1 to 6] First, fluororubber was wound around a roll mixer adjusted to have a roll interval of 5 to 10 mm, and carbon was sequentially added at the ratios shown in Table 1.
Sodium stearate, magnesium oxide and calcium hydroxide were added and kneaded. After that, roll interval is 1m
It was adjusted to m and masticated about 10 times. For the purpose of preventing frictional heat at this time, cooling water was constantly flowed in the roll to keep the roll temperature at 60 ° C or lower. Next, the cooling water was stopped, steam was passed through the roll, and the rubber temperature was 70 °.
The temperature was adjusted so as to be not lower than C and not higher than 90 ° C., then the roll interval was returned to about 5 to 10 mm, and the low molecular weight fluoropolymer was added in small amounts, and kneaded at the ratios shown in Tables 1 and 2. . Then, the roll interval was again narrowed to 1 mm and mastication was performed about 10 times.

A 150 × 150 × 1t (mm) sheet in the compound obtained in the above steps was subjected to primary vulcanization (170 ° C., 10 minutes, press pressure 7 kgf / cm ² ),
And secondary vulcanization (230 ° C., 16 hours, free).

[Comparative Examples 7 to 8] Specimens were obtained for the materials used for the sliding bodies of the conventional guide shoes.

In Comparative Example 7, the molded body obtained by ordinary compression molding was processed into each test piece by machining, and in Comparative Example 8, each test piece was molded by injection molding.

The friction / wear characteristics, non-adhesiveness and general characteristics of each of the test pieces obtained as described above were determined. Each test method is as follows. (A) Friction / Abrasion Test The obtained sheet was processed into an inner diameter of φ17 mm and an outer diameter of φ21 mm, and the SPCC of φ17 × φ21 × 10 (mm) was processed.
A ring-shaped test piece was adhered to the ring piece. The partner material is S
UJ2 (bearing steel) φ6 × φ33 × 6 (mm) cylindrical test pieces were used and evaluated with a thrust type friction tester.

The test conditions were a sliding speed of 128 m / min,
Tables 3 and 4 show the friction coefficient and wear coefficient (× 10 ⁻¹⁰ cm ³ / kgf · m) after 500 hours when the surface pressure was 3.5 kgf / cm ² . (B) Elastic body property evaluation test The tensile strength, elongation, and hardness (JIS-A) of the obtained sheet-shaped test piece were determined according to JIS-K6301.
The results are shown in Tables 3 and 4.

[0089]

[Table 3]

[0090]

[Table 4]

As is clear from the results shown in Table 4, the test pieces of Comparative Examples, which were composed of the composition of fluororubber alone or the composition of fluororubber to which ETFE or low molecular weight TFE was added,
The friction coefficient was high and the sliding characteristics were not durable. Also,
Similar results were obtained with the test piece of the comparative example made of NBR.

On the other hand, the test pieces of the examples have both a low coefficient of friction and wear resistance, and have been found to have the same level of properties as existing materials.

[Examples 10 to 18 and Comparative Examples 9 to 14] Examples 10 to 18 relate to the second embodiment of the present invention. The basic compositions of the synthetic rubbers used in Examples and Comparative Examples are shown below. [NBR basic formulation A] (high nitrile type, nitrile amount 36 to 42%): Japan Synthetic Rubber Co., Ltd .: JSR220S 100 parts by weight Sodium stearate: General industrial material 1 part by weight Carbon black: FEF 30 parts by weight Vulcanization accelerator 1 : Ouchi Shinko Chemical Industry Co., Ltd .: TF 2 parts by weight Vulcanization accelerator 2: Ouchi Shinko Chemical Industry Co., Ltd .: M 2 parts by weight Vulcanization aid: Zinc oxide (activated zinc white) 10 parts by weight Vulcanizing agent: Sulfur 1 part by weight Anti-aging agent: amino-based 3.5 parts by weight [NBR basic compounding B] (Medium nitrile type, nitrile amount 24-30%) Nippon Synthetic Rubber Co., Ltd .: JSR240S 100 parts by weight Sodium stearate: General industrial material 1 part by weight Carbon black: FEF 30 parts by weight Vulcanization accelerator 1: Ouchi Shinko Chemical Co., Ltd .: TF 2 parts by weight Vulcanization accelerator 2: Ouchi Shinko Chemical Co., Ltd .: M2 Parts Vulcanization aid: zinc oxide (active zinc white) 10 parts by weight Vulcanizing agent: sulfur 1 part by weight Anti-aging agent: amino-based 3.5 parts by weight [lubricant] (1) graphite coprecipitated PTFE [PTFE-1 After the completion of the polymerization by emulsion polymerization, it was obtained by coprecipitation with graphite having an average particle size of 6 μm in a weight ratio of 7: 3, coagulation and washing.

(2) Graphite and dry blend PTFE [P
TFE-2] PTFE (Lubricant L182J) manufactured by Asahi Glass Co., Ltd. was dry blended with graphite having an average particle size of 6 μm in a Henschel mixer at a weight ratio of 7: 3.

(3) PTFE [PTFE-3] Asahi Glass Co., Ltd .: PTFE Lubricant L182J (4) ETFE (Asahi Glass Co., Ltd .: Aflon COP Z88)
20) (5) Spherical graphite (Bellpearl C2000 manufactured by Kanebo) (6) Silicone oil (KF9 manufactured by Shin-Etsu Silicone)
6-300) [Examples 10 to 18, Comparative Examples 9 to 13] First, NBR was applied to a roll mixer adjusted to a roll interval of about 5 to 10 mm.
Wrap (220S), basic mix A or basic mix B
The antioxidant, carbon, sulfur, and vulcanization accelerator were sequentially mixed as the filler in the proportions shown in Table 5, and finally, in Table 5 or Table 6.
PTFE and other fillers were kneaded in the proportions shown in.

Thereafter, the roll interval was adjusted to 1 mm, and thin threading was performed 10 times. In order to prevent frictional heat at this time, cooling water is constantly passed through the roll to keep the roll temperature at 60
The temperature was kept below ° C. Next, stop the cooling water and adjust the rubber temperature to 70 ° C or more and 90 ° C or less by passing steam through the rolls, and then perform thinning 10 times with a roll interval of 1 mm to obtain a compound of 10 kg each. It was

The compound obtained as described above was press-molded with a mold having a length of 300 mm, a width of 300 mm and a thickness of 1 mm, and primary vulcanization (160 ° C., 10 minutes, press pressure 1
20 kgf / mm ² ) and secondary vulcanization (150 ° C, 4
Time, free). Friction and wear characteristics, non-adhesiveness, and mechanical characteristics of each sheet-shaped test piece that had been vulcanized in this manner were determined.

[0098]

[Table 5]

[0099]

[Table 6]

[0100]

[Table 7]

[0101]

[Table 8]

Incidentally, the composition of the numerical values shown in the above table and the like, which are above the lower limit and below the upper limit or above the lower limit but below the upper limit,
It may be appropriately selected so as to provide a guide shoe most suitable as a characteristic value or the like.

[Comparative Example 14] In the same manner as in Comparative Example 10,
A compound of NBR basic formulation B was prepared and a test piece was molded. A commercially available coating agent for rubber (Emullon 345, manufactured by Nippon Acheson Co., Ltd.) was formed on this test piece by a spray coating method to form a film having a thickness of about 15 μm. After coating, it was dried in an electric furnace at 80 ° C. for about 1 hour, and baked for 2 hours to complete a test piece.

For the test piece thus obtained,
The test was evaluated in the same manner as in Comparative Example 9, and the results are also shown in Table 8.

As is clear from Tables 7 and 8, Comparative Example 9 containing only the general NBR compound had a high friction coefficient and a large amount of wear. Further, in each of Comparative Examples 7 and 8 in which PTFE was added to NBR, the friction coefficient was slightly lower than that of the rubber base material, but the wear characteristics were not sufficient. Further, in Comparative Example 12 containing spheroidal graphite, the wear resistance was improved, but the friction coefficient was as large as about 0.8,
Even in the actual machine test, the followability gradually deteriorated. In Comparative Example 13 containing silicone oil, the mechanical strength was remarkably lowered and the abrasion resistance was also extremely poor.

On the other hand, Example 10 in which a powdery PTFE having a carbon material protruding on the surface and spherical graphite were added together
In No. 17, the mechanical strength did not decrease so much and the friction coefficient and wear resistance were excellent, and stable low friction and wear characteristics could be confirmed in the actual machine test. In addition, Example 18 is
Since spheroidal graphite was added together with PTFE, it had low friction and low wear characteristics as compared with the comparative example, and could withstand use like other examples.

[0107]

As described above, in the guide shoe of the present invention, the sliding body itself has rubber-like elastic characteristics, and also has low friction characteristics and wear resistance, so that the rubber elasticity of the conventional product is reduced. It is possible to eliminate the structure in which the bodies are integrally connected, and thus it is possible to achieve simplification of the structure and the manufacturing process, a significant reduction in the defective rate during manufacturing, a stable quality, and a cost reduction.

Further, since the sliding body of the present invention is excellent in friction and wear characteristics, it contributes to prolonging the life of the guide shoe.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a conventional product.

FIG. 3 is an enlarged view schematically showing a tetrafluoroethylene-based resin powder in which a carbon material is projected on the surface.

[Explanation of symbols]

 1 Mounting bracket 2 Sliding body

Claims (13)

[Claims] 1. A mounting bracket connected to a lower portion of a moving body,
A sliding body integrally attached to the mounting bracket, the sliding body being made of a lubricating rubber composition, and engaging with a groove provided in a mating guide member to smoothly guide the moving body. The lubricating rubber composition comprises a fluororubber which is a first essential component, a thermoplastic fluororesin which is a second essential component, and a low molecular weight fluorine-containing compound having a number average molecular weight of 5 × 10 ⁴ or less which is a third essential component. A polymer and a blending weight ratio of the first essential component and the second essential component is 50:50 to 95: 5.
And the compounding amount of the third essential component is 5 to 50 parts by weight with respect to 100 parts by weight in total of the first essential component and the second essential component. 2. The fluororubber which is the first essential component,
Vinylidene fluoride-fluoropropylene copolymer, tetrafluoroethylene-propylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, fluorosilicone fluororubber The guide shoe according to claim 1, which is one or more kinds of fluororubber selected from the group consisting of and fluororubber. 3. The thermoplastic fluororesin as the second essential component is a tetrafluoroethylene-ethylene copolymer, a tetrafluoroethylene-perfluoroalkylvinylether copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer. The guide shoe according to claim 1, which is one or more polymers selected from the group consisting of: 4. The low molecular weight fluoropolymer which is the third essential component is one or more polymers selected from the group consisting of tetrafluoroethylene polymers, fluoropolyethers and polyfluoroalkyl group-containing compounds. The guide shoe according to claim 1. 5. The guide shoe according to claim 1, wherein the low molecular weight fluoropolymer which is the third essential component is a tetrafluoroethylene polymer having an average particle size of 5 μm or less. 6. The lubricating rubber composition further comprising 5 to 20% by weight of the total amount of the composition of a cured powder of a thermosetting resin or a thermoplastic resin powder having a glass transition point of 300 ° C. or higher. Guide shoe. 7. A mounting bracket connected to a lower portion of the moving body,
A sliding body integrally attached to the mounting bracket, the sliding body being made of a lubricating rubber composition, and engaging with a groove provided in a mating guide member to smoothly guide the moving body. The lubricating rubber composition has a tetrafluoroethylene-based resin powder and a cured powder of a thermosetting resin or a glass transition point of 3 with an acrylonitrile-butadiene-based rubber as a base material.
A guide shoe comprising a blend of thermoplastic resin powder having a temperature of 00 ° C or higher. 8. The guide shoe according to claim 7, wherein the cured powder of the thermosetting resin or the thermoplastic resin powder having a glass transition point of 300 ° C. or higher is a spherical graphite material. 9. A tetrafluoroethylene-based resin powder,
9. The guide shoe according to claim 7, which is a tetrafluoroethylene-based resin powder having a carbon material protruding on the surface obtained by coprecipitation with a carbon material after the completion of emulsion polymerization. 10. The guide according to claim 7, wherein the tetrafluoroethylene-based resin powder is a tetrafluoroethylene-based resin powder having a carbon material protruding on the surface obtained by dry-mixing a tetrafluoroethylene resin and a carbon material. Shoe. 11. The blending weight ratio of the components is such that 10 to 100 parts by weight of tetrafluoroethylene-based resin powder, 100% by weight of acrylonitrile-butadiene rubber, and a cured powder of thermosetting resin or a glass transition point of 300 ° C. The guide shoe according to claim 7, wherein the thermoplastic resin powder is 5 to 80 parts by weight. 12. The guide shoe according to claim 8, wherein the compounding weight ratio of the components is 10 to 100 parts by weight of tetrafluoroethylene resin powder and 5 to 80 parts by weight of spherical graphite to 100 parts by weight of acrylonitrile butadiene rubber. . 13. The moving body is an elevator door,
The guide shoe for an elevator door according to claim 1, wherein the counterpart guide member has a threshold groove provided at an entrance of the elevator.